Interpretive Summary: Metabolic profiles are routinely available from human bio-fluids such as plasma and urine and can be used to indicate health status and also suggest areas of metabolic dysfunction. Research goals to understand how diet affects health and metabolism are generally broader with information obtained from bio-fluids and organ systems within the body providing more definitive patterns of metabolism that reflect disease or dysfunction. Sampling organs in humans is not feasible but can be a feature of animal models and can be particularly informative with animals that have metabolism similar to human. The current study shows a comprehensive non-targeted metabolic profiling technique of bio-fluids and tissues representing major organ systems that were analyzed in an Ossabaw pig model of diet-induced obesity. The results demonstrate that there is an extensive metabolic impact of a high fat diet on pig metabolic homeostasis indicated by metabolic alterations throughout all the analyzed sample types including plasma, urine, bile, liver, pancreas, brain cortex, intestinal jejunum and proximal colon. The analysis shows that non-targeted metabolite profiling that involves multiple sample types is feasible for the examination of a wide spectrum of metabolic species extending from small water soluble metabolites to an array of bile acids and lipids, thus pointing to the pathways of metabolism affected by the dietary treatment. The Ossabaw pig is a particularly good model of obesity because it expresses all of the features of human metabolic syndrome when fed obesogenic diets. The results of this study are important to researchers that study the effects of diet on metabolic dysfunction and how improved diets can enhance nutrition and health.

Technical Abstract:
Typical samples like urine and plasma from human nutritional studies do not provide adequate information about metabolic changes taking place in tissues after different dietary habits. For example, the link between excess caloric intake and development of obesity and related syndromes is clear, but the actual molecular mechanisms at the organ or whole-body level are poorly characterized. For this reason, inclusion of animal trials is necessitated. Furthermore, the metabolic effects related to dietary habits are typically addressed with a narrow pre-determined set of clinical biomarkers, which provide information only about certain metabolic routes or conditions, and therefore utilization of a large-scale non-targeted metabolomic approach is preferable. Here we show the extensive metabolic impact that a high fat diet has on pig metabolic homeostasis, as evidenced by metabolic alterations throughout all the analyzed sample types, including plasma, urine, bile, liver, pancreas, brain cortex, intestinal jejunum and proximal colon. Our analysis shows that the non-targeted metabolite profiling involving multiple sample types is feasible for the examination of a wide spectrum of metabolic species extending from small water soluble metabolites like betaine to an array of bile acids and lipids, thus pointing to the pathways of metabolism affected by the dietary treatment.